Centrifugal pulp-screen.



A. l. H-AUG. CENTRlFUGAL PULP SCREEN. APPLICATION mio Junin 29. 1910.

A. 1. HAUG.

CENTRIFUGAL PULP SCREEN.

APPLlCATION F|LE'JUNE29,1910.

Patented July 20, 1915.

3 SHEETS-SHEET 2.

i@ /WM .ANTON J. .HA-UG, F NASHU'A, NEWT HAIVFSHIRE, ASSIG'NOR TO THEIMPRCVED PAPER MACHINERY COMPANY, OF NASHUA, NEVI HAMPSHIRE.

Specification of Letters Patent.

Patented Jnly 2G, 33315.

continuationof @pasaran serial no. 545,856, 'flied February 24, 1ero,This application sied nine 29,1910.

' Serial No. 569,457.

To' all `whoif t muy concern. 3e it lnovvn that Anz-'ron J. Hann, asubject of the Emperor of Germany, and a resident of Nashua; in thecounty of Hills- Lb'o'ro, State of New Hampshire, United States ofAmerica, have invented certain new and useful Improvements inCentrifugal Pulp-Screens, of'vvhich the following is a specilication.y.'

The vobject ofiny invention is to' produce ahcehtri''ug'al screen havingvcertain fea-tures ot'fnovetlyand advantage, particularly as relg'tes tothe metliod-offfeeding the pulp to thescreen." v -*My linvention isillustrated and described as, en1bodied in a machine for screening "'.ffpaiperrpulp and the object of the inventionl 1s in general'fto increasethe elliciency of inachines of this character and to produce a niachinehaving certain features of novelty ints construction and mede cliop'era'ticn. j'This application is a continuation of my priorapplication Serial No.- 534.5,886T filed Feb.' 24, 1910. f..

1' bodgyingfrny invention.' Fig `is an end v ieyv'of'the same. Fig. is atransverse sectional vien', the impeller being shown in full lines.'Fig. 4i .is a detailed View of the iinpeller.

t; 'll/lachincsfol this'general type and the pui-pose for Iwhich theyare used are gen erallyi'known and it will sullice here Vto say thatthe/ pare :utilized to separate the fibers 1 off ),ulp which aresuitable nto be made into i pa'per vfrom, lthe larger or coarser fibers.sliiiers, etc., which are not suitablel for such use. In generalmachines of-this type `coni- 4 sc' en which may or may not 'berotatable. Y Hthin this screen there a shattwhicl'i'.roM

tates ata quite high rate of speed and carries/an impellcr Withbladesextending tho length of the` screen Afor the purpose oli throwing the.stock with force against the 1 screen. The stock is 'fed into'theinterior of th reen, thrownby the blades against theth screen, thecoarser particles which cannot get througlr'thescreen, working their1in. wa-yhoutTodi-the endsz' These coarsor fibers j are lcd intoseparate conduits from the n theidi'aWings-fFigure lis a 'side View f vl in' central vertical section of a machine e1'ntheI screen.'

with respect to tho direction ol rotation ci.;

e a. casing Within which is n'iountedlalf" eenj, and'tl 1e`"line fibersarc forced through screened libers `here they discharged r from themachine, i 5 The machine illustrated is of the hori?` zontal type andthe traine is made up ot thc end castings a a. and the cylindricalcasing.; il) secured to the end castinfs; 'the cylindrical gi screen cis otsinaller diameter than the caso0 ingand is supported at its ends onaniiular-. fianges al projecting inwardly troni `the en j Walls. xlsshown each `end Vof the screen is i provided with a gear c and isadapted .to be@ driven bythe piniorrc2 which in turn may 65 bedriven inany desiredlinanncr. .l a main sui'iplyh tank located at one side o1 themachiiu` and-having branches J1 rZg. extending: around to cach end ofthe machine con'nnunicating fivith parti-ampliar spouts'o c c whichproject through the end Wall o' l.1 the'frame into thc interior ci? thescreen.'-L

f their inner ci'idsare perforated, ttrpi'ovilic..

passagestiii'ough which thc stoel; aan be `ted I75 to thc interior otthc screen, the size and' I niunbcr1 ot' the peigliorations beingreduced i toivard thcY lower endsot the spous in Qrdei.'

to provide an eren distribution ci stock to c;

Allxtcnding;` centrally throur'h the inacliincl, and supported insuitablebearings is a shaft at the center ofivhich is a huh supporting ga spider, tothe outer edge ot' which are sc-A c. cui-od inipcllcrblades'Those blades cx- ,85 tend to cithcr side ot thc conter. and partly flill the spaces between the spouts andthe,A screen. lil/hen `sccn inedge View they are oppositely inclined i'roni the center ou ivardly,this inclination beingA to the rear L arey the sliver outlets arrangcdntcach end of the n'iachinc linto which the` un,- 95 screened Imaterialsare delivered. .f'\s thcrgl pulp is delivered Yfrom the 'feed spouis to@the interior otj tl'ie'scrrcn it is piclcdnpvby 1 the blades and thrownforcibly against-thcA l screen drinn,

The screening operation i'sl 00 practically an instantaneous onooccurring l atthc moment of impact of the pulp on the screen, and suchstock as is not screened atl this-first impact will bc carried anfaywith the,;v slivcrs and' lost/unless iurthcr moans are pro- 105 ridedfor subjecting it to the screening action.

lt will be understood that the stock is originally vfed to the screennear its central portiomiind because of the inclination of the blades itis thrown against the screen at a slight angle to its surface, and thegeneral direction which is imparted to it is toward both ends of thescreen drum. The screening operation is a continuous one and there is acontinuous stream ot pulp being thrown against the screening drum, andin consequence the unscreened particles which lodge on the innersurfaceoit' the screen are continually :forced toward the ends otl the screento the sliver outlets.

ln order to prevent the waste of good stock. which might otherwise becarried away with the slivers, I project into each end ol. the screen,and preferably under ncath the center, shower pipes 20-20, which. arearranged inside ot' the impellcr blades and are pierced on the side nextto the imheller blades. rl`he water as it comes from these pipes ispicked up by the impellcr blades and thrown against the screen in theform ot' a spray, washing through the creen any stock which is collectedon tlif` interior oi' the screen and is being carried along witl. theslivers. This is a continuous screening operation to which all of thestockl which was not screened at theftirst impact is subjected. and theresult is'a very greatly increased elleiency iu the screening operationby which the loss olf pulp is minimized.

Another advantage in the use of the oppositelyinclined bladesl is thatthe s'livers travel l'rom the center toward each end of the screeninstead olf having to travel the full length ol. the screen thus makingit possible, to maintain the inner surface of the screen drumin acleaner condition. and so materially increase, the cllicieney of themachine. i y

vIn the structure illustrated and described herein the, screen drum isintended to rotate in the direction opposite to that ot theI impeller,and in order to prevent the slivcrs from traveling around and around onthe inner surl'ace ot the screen, and also to wash back into the, screenany particles of fiber which Vhave become wedged, I provide a showerpipe 25, which :is located within the casing outside ol' the screen, andextends the leu` h ol' theI screen. This shower pipe is arranged toproject the water against the upwardly moving side ol the screen justheyond the point where the interior pipes 20-20 are arranged, and washesthe thickencd stock which may have collected on the inner surface of thescreen down under the interior shower pipes 20-2O,1where they aresubjected to the spraying action of the water delivered by these pipes.l

In order to preventl theI settling of the pulp in the feeding spouts andmaintain the stock as fed to the screen in uniform condition I introduceat the outer end of each spout jets of air, water, or the like, throughthe pipes 2, 2, preferably under a pressure which is greater than thepressure of the pulp in the inlets, with theresult that this waterwashes any thickened or settled pulp out of the spouts into the screen.These jets are projected toward the lowest points of the feed spouts norder to thoroughly cleansethem.

The screening ot the pulp stock to be used in the manufacture ot paperis of great im poi-tance. It is essential that the screening be, donethoroughly and uniformly, that al1 stock which is suitable for use shallbe passed tln'ou'gh the screen, that the stock not suitable for useshall be prevented from passing through the screen and that thescreening operation Shall he accomplished in the shortest possible spaceof time. l

The machine herein illustrated and described possesses features ofmaterial advantage over those heretofore used in the followingparticulars. The feeding of the pulp into each end of the machine andthe graduation of the outlet apertures in the feed spouls insure an evendistribution of the stock to the impeller blades. The oppositeinclination of the blades insures the cleaning ot the inner surface etthe screen in the shortest possible time by causing the slivers totravel toward each end of the screen,;and in connection with the doubleend feeding of stock to the machine greatly increases the capacity olthe machine without the use of additional power. Furthermore theopposite inclination ol each of the blades tends to balance them,reducing the end thrust and wear of the parts. The useof the interiorshower pipes reduces toa minimum the loss of pulp, and insures a mostthorough screening` particularly when utilized in connection with theoutside shower pipe 25.

The arrangement 'of the main supply tank at one side of the machineiwithbranches extending to each end and communicating with the feed spouts isof advantage both as regards the small amount otloor space required forthe machine andin insuring 1mi-4 formity of distribution of the stock toeach end of the machine and to the screen. The provision for thinningany stock which has collected in the feed spouts and for Washing out thefeed spouts hy waterfjets under a higher pressure than the pressure withwhich the stock is fed into the spouts insures the maintenance of themachine in a condition ol' the greatest efficiency.

It is to be remembered that-'the paper stock is quite expensive and thatthe losses of good stock which would occur if the screening operationwere not thoroughly and effectively carried out would amount toconsiderable sums each working day. It ifl of the utmost importancetherefore that proincassa v Vision be made, for establishing and main`taining the highest possible eliciency of inachines of this type and theherein illustrated and described machine has been designed with this endin View.

,l claiml 1.111 a machine of the character described the combinationwith the casing, a druiii located therein, a stock inlet communicatingwith the interior ot said screen drain, a pulp loutlet communicating`.with the interior olf said easing, a `plurality of sliver outletsceinniunicating with the interior et said screen drum. a rotatablepaddle blade support, oppositely arranged paddle blades supportedthereby, said paddle blades being inclined rearwardly from end to endtoward Said sliver outlets, whereby the unscreened stockis caused to'travel in yopposite directions on the inner surface of said screen drinntoward saidl sliver outlets.

2.111v a machine -ot the character de-l scribed, .the combination with acasing," a

screen drum located therein, a stock inlet communicating with theinterior of said screen drain, a pulp outlet communicating,T

with the interior Aof said'casing', a plurality of sliver outletscommunicating with the 1nterior of said screenidrum, a rotatablesupposite directions alongl the inner surface said screen drain towardsaid sliver outlets.

3. ln a' machine of the character described ther combination with. acasing, aV cylindrical rotatable Vscreen mounted therein, means iter'rotating the same, a feed spout extending into said screen, a shaftcarrying iiaddle `blades klocated between said spout and said screen, ashower pipe extending in'to'said screen inside of said paddlel blades*and adapted to-delii'er water thereto, and a second shower'pipe.arranged i'n proximity to- `the'exterior oi said screen drum at a peintbeyond the iii-st outward `pipe in the direc-` tion ol' rotation of thescreen.

ln:` a centrifueal niliiscreenof the hors l izontal type, a casing, aIcylindrical screen ,ziiiount'edf therein, pulp inlets arranged' at eachend of the machine and extending' into the interior oil? the screen andspaced theretroni, sliver outlets at each end of the niachiiie incommunication with the interior zot the screen drum, a pulp outlet incommunication with the interior of the easing.v ya sha tftexteiidingthrough said casing, paddle bladessupported from said shaft centrally iof the machinefand arranged in pairscx# tending''toWard-th'e ends of themachine.

' one side of said casing, feed pipes extending from said tank to each.end et said casing and discharging within said screen at each endthereof. i

o. ln a machine of the character described the combination with a casingand a cylin-` drical-screen mounted therein, et parti-an nular feedspouts extending int-o said screens Afroin'eaeh end thereof, the outersurfaces of said spouts which lie within said screen have"A ina`discharge orificesnear their inner ends.

i; in a machine of lthe character de@ scribed, the combina-tion with acasing'and a cylindrical screen mounted therein, of

parti-annular feed spouts arranged. at each end of said casing andextending within.v said screen, the opposite ends of said sp'outs bei-ngoppositely inclined, discharge apertures through the exterior walls ofthe inner' ends of said spouts, the capacity of said discharge orificesincreasing troniv the lower to the upper parts of' said spouts. 1" v S.lin a "machine -oi"'"the character de-f scribed, the combinationljwithacasing' and av cylindrical screen locatedy therein, of a roe' taryiinpellervlocated within said Screen, said' iinpeller comprising'a hubandiblades sup-1j` ported therefrom, said blades when seen inv edgei'iew:beingv lopiiositely inclined from'v the center rearwardly with respect:to their direction of rotation.

il. In a iiiaehineof the character described a easingrya cylindrical'screen mounted with# in vsaid casing' and supported tlu-reby, av rotary"shallt supported `in siii-table"bearings in said'casingrandI'ext-eridint ,through said screen,v and an inipeller coin.)risingiva'li`ibf secured to said'shaft 'centrallyo hei'leiigrt'hf of saidsci-een, r ai is, projeetiine;` rid"i`ll `i, f}` troni "said huh,v andblades 'extending ffronir oppositesides'ot `d arinsandllocated-'in'proximity to kthe nnen/surface of said:` screen. y 1 y it?. ln'a machinefthe character described a casinggacy indiic `,l screen mount# ed withinsaid easiii'giand ipporte'il,there-l by, av rotary shiittsui'iI ortedsuitablev bearings in iid' casing.. and` extendingy through saidAeein'and an iijiipeller com?l prising ahiib secured toy saidv lshaftcentrally ot' the length ot' said screen, arms projecting. radiallytroni, said hub, and blades extend-f, iup; from opposite sides of saidarms and located in proximity to the inner surface 0f Said screen, saidbladesl being inclined rearwardly with respect' to their direction ofrotation.

11. In a machine of the character described, the combination with a c:t' l a cylindrical screen mounted therein.y feed ,spouts extendingthrough the end walls o'lE 4said casing within said screen`r thc inner ilocated between the exterior surfaces ol said spout and said screen.

1'2. In a machine of the. character de scribed, thevcomhination with acasing and a cylindrical screen. located therein, ot' a parti-annularfeed spout extending within said Screen and .a lluid supplyv pipeextending into the lower parts of said spout for the purposes specified.

13. 1n a machine of the character described, the combination with acasing` a screen drum located therein. means for ins treducing Stockwithin said drum, a pulp outlet in con'nnnni'cation with the interior ofthe casing, a sli'ver outlet in comnmnication with the interior ol thedrum, and means for feeding the stock in oppositedirections within saiddrum.

14. 1n a machine of the cl'iaracter (le-- scribed, the combination witha casing, a screen drum located therein, means 'for introducing stockwithin. said drum a pulp outlet in con'nnunication with the interior otthe casing, a sliver outlet in communication with the interior otthe'drum, and means for feeding the stockin opposite directions withinsaid drum, said means comprising oppositely arranged rotatal'ile paddieblades within the drum inclined in opposite directions with reference tothe direction of rotation from the ends ot' the drum toward anintermediate point therein.

15. 1n a centrifugal screen of the horizontal type, a casing, acylindrical screen mounted therein, pulp inlets arranged at each end ofthe screen and extending into the interior of the screen and spacedtherefrom, sliver outlets at'each end ofthe screen in communication withthe interior of the screen drum, a pulp outlet in communication with theinterior ot the shaft, a rotatable paddle blade support and paddleblades supported thereby located in and adapted to rotate throughthe'space between the screen drinn and the pulp inlets, said bladesbeing inclined from end toe end rearwardly with respect to theirdirection of rotation wheres by the unscreened materials are caused totravelitoward each end of said screen drum.

16. 1n a centrifugal pulp screen of the horizontal type. a casing, acylindrical screen mounted therein, pulp inlets arranged at: each end ofthe screen and extending `into the interior ot the .screen and spacedtheret'rom` a sliver outlety in communication with the interior ot' thescreen drum, a pulp outlet in conmumication with the. interior ol thecasing. a rotatable paddle blade support, paddle blades supportedthereby located in and adapted to rotate in the space located betweenthe screen drum and the pulp inlets, said blades being inclined l'romend to end rearwartltr with respect to their direction otf rotationwherein' tl c nnscrcened mater rials are caused to travel in oppositedirections.

1T. ln a centrifugal pulp screen oli'the horizontal tvpc. a casing. a c\'lindrical screen mounted therein. pulp inlets arranged at. each endoll thc machine and extending into the interior ol' thc yscreen andsl'iaced therc'lrom, sliver outlets at each end ol' the machine incommunication with the interior ot' the screen drum, a pulp outlet inconn munication with the interior of the casing. and means tor causitng`the nnscremied matcrial:` lo trarel toward each end of the drum lrom theinterna-dude portion thereof.

lo. machine oll thc character described comprising a casing. ac.\f'linitrical screen mounted therein. a supply tank arranged cX-terior but coi'itiguous to the casing, leed pipes extending lrom saidtank to each end otl said casing and discharging within said screen .atcach cnd thcrcot,A sliver outlets connmmicating' with each cial o'lf thescreen, a pulp ont.ct commcnicating with the interior ol' the casing andpaddle. blades inclined t ith relation to the direction ot' roltationlor propelling the nm-'|'ee.mnl matcrial in opposite directions withinsaid screen toward said sliver outlets.

lf). A machine o'f thc character describedcomprising a casing. a cylirulrical screen mounted therein, a supply tank arranged exterior butcontiguous to said casing; 'feed pipes extending from said tank to eachend o'l said casing and discharging within said screen at each endthereof, a sliver outlet. n -ans conmmnicating with the interior of thescreen, .a pulp out-let comnmnicating with the. casing and paddle bladesinclined with relation to the direction ol rotation for moving theunscreened material within the screen in opposite directions from the.feed pipes,

20. ln a machine o'l' the clniracter described. the combination with acasing, a cylindrical screen located therein` sliver outlet meanscommunicating with the interior ol' said screen, pulp outlet meanscomn'innicating with the, casing. and a. rotar)r iinpeller locatedwithin said screen con'iprising a rotary support and opposite sets ofblades carriedthereby, the blades at opposite ends of the impeller whenseen 1n edge View being oppositely inclined from the center outward withrespect to their 'direction of rotation.

2l. In a machine of thev character described, tlie combination with acasing, a cylindrical screen mounted therein, eed spouts` extendingthrough the end Wallsrof said casing within said screen, the inner endsof saidy spouts being spaced from one another and the exterior surfacesthereof being spaced from said screen, a sliver outlet communicating ateach lend with the in* terior of the screen, a pulp outlet communieatingwith the casing, and a rotary im peller located within said screencomprising a rotary paddle blade support between the ends of the spoutsand 'blades se'cured to and extending4 laterally from said support inopposite directions and located between the exterior surfaces, of saidspout and said screen.

22. In a machine of the character described, the combination with acasing, a cylindrical screen mounted therein, feed spouts'extendingthrough the end walls of said casing Within said screen, the inner endsof said spouts being spaced from one another and the exterior surfacesthereof being spaced from said screen, a sliver outlet communicating ateacli end with the interior of the screen, a pulp outlet communieatingwith the casing, and a rotary impeller located within said screencomprising a rotary paddle blade support between the ends of the spoutsand blades secured to and extending laterally from said support inopposite directions and located between theexterior surfaces of saidspout and said screen, said blades being inclined rearwardly with 23. Ina machine of the character described, the combination with a casing of acylindrical 'screen/mounted therein, means for delivering stock to theinterior of the.

ANTON J. HAUG.

Witnesses n. r. Grimm, Homann PARKER.

' reference to the direction of rotation from said central supporttoward their ends.

